We were just there June 26-30 and the Brazilian tour groups were everywhere! There were red shirts, blue shirts, yellow shirts, and green shirts. They weren't rude of anything but there were hundreds of them. We made the mistake of going to Animal Kingdom the same day they did. My son and daughter went to Dinosaur right at RD (while I got FP for EE) and got behind a group of blue shirts. There were about 100 of them. The red shirts were behind my kids, so they were sandwiched between tour groupos. I wondered what was taking them so long. My kids are scarred for life when they see those shirts and flags.
I was tempted to ask one of the flag holders what their itinerary was.
I have gone in November and Feb. and this was the most I have ever seen. Again, they weren't rude in any way. They only chanted/clapped once in line but other than that they were very well behaved. Its just a very large group.
I'll upload a picture I took sometime today.